Alert archive / Colorado / Broomfield County
Weather alerts in Broomfield County, Colorado, 2011
97 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Broomfield County and its neighbors
Each county as a circle sized by its count in 2011. Tap one for its archive.
- Alerts
- 97
- Warnings
- 35
- Watches
- 22
- Advisories
- 19
- Busiest month
- July25 alerts
- Busiest day
- July 14, 20115 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 1 tornado warnings covering Broomfield County in 2011 had a tornado report inside them.
Broomfield County, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 5 | 3 | 40% | 1 | 100% | 13 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Denver/Boulder, CO: tornado warnings | 35 | 6 | 83% | 11 | 73% | 12 min |
| NWS Denver/Boulder, CO: severe thunderstorm warnings | 212 | 85 | 60% | 251 | 65% | 19 min |
| NWS Denver/Boulder, CO: flash flood warnings | 36 | 6 | 83% | 7 | 86% | 68 min |
An office's figures cover every county it serves, including across state lines.
Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.
The alerts
Every alert, in the order issued. Times are local, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 7, 2:53 PM MST | Winter Storm Watch | BOU | 25 hr |
| Jan 8, 3:52 PM MST | Winter Weather Advisory | BOU | 41 hr |
| Jan 30, 3:13 PM MST | Winter Weather Advisory | BOU | 33 hr |
| Jan 31, 4:10 PM MST | Wind Chill Warning | BOU | 44 hr |
| Feb 1, 3:25 PM MST | Wind Chill Advisory | BOU | 18 hr |
| Feb 5, 2:33 PM MST | Winter Weather Advisory | BOU | 5 hr |
| Feb 6, 3:57 AM MST | Winter Weather Advisory | BOU | 12 hr |
| Feb 6, 3:52 PM MST | Winter Weather Advisory | BOU | 44 hr |
| Feb 28, 11:20 AM MST | Red Flag Warning | BOU | 6 hr |
| Mar 10, 4:37 AM MST | Fire Weather Watch | BOU | 11 hr |
| Mar 10, 3:39 PM MST | Red Flag Warning | BOU | 26 hr |
| Mar 15, 2:43 PM MDT | Fire Weather Watch | BOU | 34 hr |
| Mar 15, 2:43 PM MDT | Red Flag Warning | BOU | 29 hr |
| Mar 15, 2:43 PM MDT | Red Flag Warning | BOU | 52 hr |
| Mar 20, 3:57 AM MDT | Fire Weather Watch | BOU | 9 hr |
| Mar 20, 12:41 PM MDT | Red Flag Warning | BOU | 33 hr |
| Mar 21, 4:31 AM MDT | Fire Weather Watch | BOU | 10 hr |
| Mar 21, 2:45 PM MDT | Red Flag Warning | BOU | 31 hr |
| Mar 22, 3:49 AM MDT | High Wind Watch | BOU | 7 hr |
| Mar 22, 10:35 AM MDT | High Wind Warning | BOU | 11 hr |
| Mar 22, 10:06 PM MDT | High Wind Warning | BOU | 4 hr |
| Mar 24, 2:38 AM MDT | Red Flag Warning | BOU | 17 hr |
| Mar 30, 4:03 PM MDT | Red Flag Warning | BOU | 26 hr |
| Apr 1, 4:20 AM MDT | Fire Weather Watch | BOU | 11 hr |
| Apr 1, 3:34 PM MDT | Red Flag Warning | BOU | 44 hr |
| Apr 4, 3:51 PM MDT | Red Flag Warning | BOU | 28 hr |
| Apr 6, 2:28 PM MDT | Fire Weather Watch | BOU | 24 hr |
| Apr 7, 2:47 PM MDT | Fire Weather Watch | BOU | 23 hr |
| Apr 7, 2:47 PM MDT | Red Flag Warning | BOU | 29 hr |
| Apr 8, 2:01 PM MDT | Red Flag Warning | BOU | 31 hr |
| May 8, 4:02 PM MDT | Red Flag Warning | BOU | 28 hr |
| May 18, 1:13 PM MDT | Tornado Warning | BOU | 31 min |
| May 18, 2:16 PM MDT | Areal Flood Advisory | BOU | 119 min |
| May 18, 2:38 PM MDT | Severe Thunderstorm Warning | BOU | 19 min |
| May 23, 2:17 PM MDT | Mesoscale Discussion | SPC | 88 min |
| May 29, 3:35 PM MDT | High Wind Watch | BOU | 14 hr |
| Jun 1, 4:12 PM MDT | Red Flag Warning | BOU | 28 hr |
| Jun 8, 2:51 PM MDT | Mesoscale Discussion | SPC | 84 min |
| Jun 30, 11:57 AM MDT | Mesoscale Discussion | SPC | 63 min |
| Jun 30, 12:18 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 30, 1:49 PM MDT | Mesoscale Discussion | SPC | 116 min |
| Jun 30, 4:17 PM MDT | Mesoscale Discussion | SPC | 118 min |
| Jun 30, 7:25 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 2, 12:47 PM MDT | Mesoscale Discussion | SPC | 58 min |
| Jul 5, 3:15 AM MDT | Flash Flood Watch | BOU | 23 hr |
| Jul 6, 2:38 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Jul 7, 4:08 PM MDT | Severe Thunderstorm Warning | BOU | 46 min |
| Jul 7, 4:46 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Jul 8, 1:21 PM MDT | Severe Thunderstorm Warning | BOU | 39 min |
| Jul 8, 1:43 PM MDT | Mesoscale Discussion | SPC | 92 min |
| Jul 8, 7:04 PM MDT | Severe Thunderstorm Warning | BOU | 45 min |
| Jul 8, 7:18 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Jul 10, 1:57 PM MDT | Special Weather Statement | BOU | 48 min |
| Jul 10, 2:12 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| Jul 12, 3:49 AM MDT | Flash Flood Watch | BOU | 25 hr |
| Jul 12, 2:07 PM MDT | Mesoscale Discussion | SPC | 53 min |
| Jul 13, 2:23 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 13, 5:13 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 13, 8:12 PM MDT | Mesoscale Discussion | SPC | 63 min |
| Jul 13, 9:28 PM MDT | Areal Flood Advisory | BOU | 77 min |
| Jul 14, 5:25 AM MDT | Flash Flood Watch | BOU | 16 hr |
| Jul 14, 1:14 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 14, 2:43 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 16, 3:47 PM MDT | Mesoscale Discussion | SPC | 58 min |
| Jul 19, 4:19 PM MDT | Special Weather Statement | BOU | 26 min |
| Jul 19, 4:58 PM MDT | Special Weather Statement | BOU | 32 min |
| Jul 25, 1:32 PM MDT | Mesoscale Discussion | SPC | 88 min |
| Aug 16, 1:48 PM MDT | Mesoscale Discussion | SPC | 117 min |
| Sep 21, 4:00 PM MDT | Frost Advisory | BOU | 16 hr |
| Oct 6, 2:48 AM MDT | High Wind Warning | BOU | 16 hr |
| Oct 6, 4:27 AM MDT | Red Flag Warning | BOU | 16 hr |
| Oct 8, 2:07 PM MDT | Freeze Warning | BOU | 19 hr |
| Oct 9, 1:45 PM MDT | Frost Advisory | BOU | 18 hr |
| Oct 15, 4:25 AM MDT | Red Flag Warning | BOU | 16 hr |
| Oct 17, 4:49 AM MDT | Freeze Warning | BOU | 27 hr |
| Oct 18, 10:40 AM MDT | Freeze Warning | BOU | 21 hr |
| Oct 23, 3:29 PM MDT | Winter Storm Watch | BOU | 36 hr |
| Oct 25, 3:49 AM MDT | Winter Storm Warning | BOU | 37 hr |
| Oct 25, 5:56 PM MDT | Mesoscale Discussion | SPC | 4 hr |
| Oct 27, 4:17 AM MDT | Dense Fog Advisory | BOU | 5 hr |
| Oct 31, 5:02 AM MDT | Winter Storm Watch | BOU | 24 hr |
| Nov 1, 5:12 AM MDT | Winter Weather Advisory | BOU | 29 hr |
| Nov 1, 10:54 AM MDT | Winter Storm Warning | BOU | 25 hr |
| Nov 1, 7:13 PM MDT | Mesoscale Discussion | SPC | 5 hr |
| Nov 10, 3:23 PM MST | High Wind Watch | BOU | 12 hr |
| Nov 11, 3:04 AM MST | High Wind Warning | BOU | 51 hr |
| Nov 14, 9:46 AM MST | Red Flag Warning | BOU | 7 hr |
| Nov 29, 12:14 PM MST | Winter Storm Watch | BOU | 23 hr |
| Nov 30, 11:27 AM MST | Winter Weather Advisory | BOU | 27 hr |
| Dec 2, 7:57 PM MST | Winter Weather Advisory | BOU | 18 hr |
| Dec 3, 3:20 PM MST | Winter Weather Advisory | BOU | 32 hr |
| Dec 9, 3:48 AM MST | Dense Fog Advisory | BOU | 5 hr |
| Dec 9, 7:20 PM MST | Dense Fog Advisory | BOU | 8 hr |
| Dec 20, 2:00 PM MST | Winter Storm Watch | BOU | 15 hr |
| Dec 21, 4:33 AM MST | Winter Storm Warning | BOU | 30 hr |
| Dec 29, 3:03 PM MST | High Wind Watch | BOU | 19 hr |
| Dec 30, 10:15 AM MST | High Wind Warning | BOU | 31 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Severe storms | |
| Severe Thunderstorm Warning | 5 |
| Tornado Warning | 1 |
| Severe Thunderstorm Watch | 3 |
| Mesoscale Discussion | 18 |
| Special Weather Statement | 3 |
| Flooding | |
| Flash Flood Watch | 3 |
| Areal Flood Advisory | 4 |
| Winter | |
| Winter Storm Warning | 3 |
| Winter Storm Watch | 5 |
| Winter Weather Advisory | 9 |
| Cold | |
| Freeze Warning | 3 |
| Wind Chill Warning | 1 |
| Frost Advisory | 2 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 5 |
| High Wind Watch | 4 |
| Fire | |
| Red Flag Warning | 17 |
| Fire Weather Watch | 7 |
| Fog and smoke | |
| Dense Fog Advisory | 3 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20102012
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.